Marshall Pruett's Tech Mailbag for May 16

Fire away with your tech questions about F1, IndyCar, TUDOR Championship, WEC, Pirelli World Challenge or whatever else that comes to mind from the world of road racing. Please send them to PruettsTechMailbag@Racer.com. We can't guarantee your letter will be published, but I will always reply. -Marshall Pruett

Q: I'm a big fan of your tech mailbag and your great articles on RACER.com. After the thunderstorm passed on Sunday at Barber, I was wondering why they didn't get the IndyCars out on track any sooner as it was just wet, albeit with a few rivers across the track. I'm glad they did get out as it was an interesting race and Bourdais and Montoya both impressed until their incidents. In the post-race interview, RHR stated that the "wets" were like "intermediates." Could you talk about the differences in the inclement weather tires between IndyCar and F1? I know we don't have the budget to bring two levels of rain tires like in F1, but I thought that the rain tires in IndyCar were full wets? Gabe, Chicago, IL

MP: Firestone uses a single wet tire specification. If there’s a limited amount of standing water, the wets can handle it, but as we saw during the worst portion of the Barber downpour, Noah’s Ark would have been required to get across a few of those lakes that sprang up on the track. Dale Harrigle, Firestone Racing’s chief engineer, added this to the explanation:

Based on our experience in IndyCar, in 2012 Firestone developed a new rain tire that was a bit more like an intermediate tire then what we had used previously in IndyCar competition. Rain tires based on that design were used at this year’s Barber Race, and were perfectly suited to the drying road course track. For 2013 we released a new rain tire design that is visually quite similar, but has a bit more tread depth to handle slightly more standing water. This 2013 rain tire will be the tire used full time in IndyCar competition after the Detroit race. When Bridgestone was involved in Formula 1, we supplied three rain tire options that the teams could use at their discretion.

Q: Do PCs us the same tires as P2's and DP's? If not, would P2s race better with PC tires?Ed Joras

MP: Continental’s prototype tires are the same for PC, P2 and DP.

Q: I was going to ask why has the DeltaWing not been given more favorable treatment in the ALMS/IMSA BoP, but then I realized that it never finishes races. I like the concept behind the car, and every time I watch a race I hear how successful the concept has been. But if the car can't finish a race, regardless of whether it's part failure or crash damage, how successful has the concept actually been?Kyle in Raleigh

MP: It’s a one-off car, with no benchmark for what’s needed to compete with highly developed P2 and DP cars, so it’s not a big surprise the DW has a BoP that looks unlike anything else in the series. It’s a single car working through development on a part-time race schedule, which makes things like reliability more of a long-term solution to find. With two or three cars on track, they’d be on top of reliability by now.

It’s a success as far as I’m concerned – the car’s unique, inventive, odd, and continues the thinning bloodline of actual prototypes in sports car racing. It doesn’t come off of an assembly line, has some wacky ideas, and celebrates creativity. I’d think people would cheer the car more than any of the other cars in the Prototype class simply because it isn’t another cookie-cutter creation built to low-tech or low-cost regulations.